A Floral Anomaly Prompts
Major Advances in Science

Richard Jorgensen's idea was simple enough: make bright purple petunias by splicing into the plants an extra copy of the gene that makes purple pigment. To his astonishment, the flowers bloomed white.

That curious outcome defied genetic logic. After appearing on the cover of a prominent plant journal, the puzzling result prompted a wave of scientific inquiry. Now, more than a decade later, biologists are starting to get a handle on...